The Dreaded Grosvenor Coup

aka X-Clubs 16. How many readers are familiar with the “Grosvenor Coup”? I will try and explain it in simple terms: a defensive blunder gives the contract to declarer but it creates so much doubt in declarer’s mind that he takes a losing line when having been presented with the contract. Look up Grosvenor on Google: Grosvenor Coups used to be quite the thing some years ago. But they can still occur today, as evidenced by this deal which left your author with a huge amount of egg on his face and a bottom instead of a top on Board 26 from Friday 6/05/2022.

Dealer East EW Vul
Board 26


After a pass from East, South opened 1D, West overcalled 2C. Double from North, 3C from East, 3D from South, pass, pass back to East. What should East do? East decided that to double might invite disaster if West took it as a penalty double and passed, and 4C would probably be a bit high. Passing out 3D wasn’t going to get too many match points so East bid 3NT! Gutsy but East trusted partner’s overcall, and with a diamond stopper and likely stoppers in both majors (West had to have points in the majors, with only a maximum five count in clubs) opted for the very daring and very risky 3NT. High risk, high reward. Or maybe madness?

South led the seven of spades. Obviously looking for an entry to partner to lead a diamond through. North won the king and did as asked, returning the ten of diamonds. Declarer covered and South cashed the top diamonds. However South was convinced that declarer had held up the ace of spades at trick one, so instead of leading another spade to North’s ace for one down, decided to set up her diamond suit. Declarer now had eight tricks and the ninth could come from a heart finesse. But that had to be taken early and if it lost the result would be three or four down. Three or four down did not seem attractive, and East convinced himself that South had the ace of spades and North the king of hearts, so one down would be a good score, since then EW would be making 3D or even 3S if they had missed a spade fit. So, yours truly cashed the clubs and heart ace and conceded the last trick for one down, turning a sickly green when SOUTH showed the king! One down, which was always the case if South had led the second spade to North’s ace.

This had been a Grosvenor Coup to boast about for months, had it been perpetrated intentionally. Unfortunately there are no real exponents of the Grosvenor Coup these days, as far as I am aware.